1. Field of the Invention
The present invention relates to polyetheric copolymers, processes for preparing the same, compositions containing the same, molded products prepared from the same, and their uses.
More particularly, the present invention relates to polyetheric copolymers useful as materials in electronic and electric equipment fields and in mechanical field on account of their crystallizability, their high resistance to heat, chemicals and solvents, as well as their excellent electric properties and mechanical strength, to processes for preparing the polyetheric copolymers with a high efficiency, to compositions containing the polyetheric copolymers with their further improved resistance to heat and mechanical strength, their molded or formed products, and their uses.
2. Description of Related Art
Recently, engineering plastics having a variety of chemical structures have been developed and they lend themselves to a wide field ranging, for example, from the automobile field, the electric and the electronic fields, and precision machinery field, to the office automation instrument and the optical communication instrument fields. They are said to be still insufficient in various respects and they do not sufficiently satisfy various demands for requirements which are getting severer, so that development of a new and improved material is still required.
Polyetheric copolymers as one of the engineering plastics are particularly excellent in their resistance to heat and various polyetheric copolymers have been proposed.
Japanese Patent Publication (Kokai) No. 14,270/1972 proposes a process for preparing an aromatic polyetheric copolymer by reacting a dinitrobenzonitrile and a dihalogeno benzophenone with a divalent phenol in the presence of an alkali metal compound.
By this process, the resultant polyether copolymers, however, are low molecular weight polymers having a melt viscosity of not more than 200 poise. Therefore, they are not sufficient in a resistance to heat and mechanical strength.
Japanese Patent Publication (kokai) No. 235,835/1985 proposes a process for preparing a polyetheric copolymer by reacting a dihalogeno benzonitrile and a 4,4'-dihalogeno benzophenone simultaneously with an alkali metal salt of a divalent phenol, the polyetheric copolymer having recurring units as represented by the following general formula (a): ##STR3## and as represented by the following general formula (b): ##STR4## (wherein Ar is a divalent aromatic residue) and having a molar ratio of the recurring unit (a) to a sum of the recurring units (a) and (b) of 0.5 to 1 or higher.
It is to be noted, however, that the polyetheric copolymer having a molar ratio of the recurring unit (a) to the total of the recurring units (a) and (b) of 0.5 to 1 or higher is so amorphous that it cannot maintain its mechanical strength in a temperature range beyond its glass transition temperature. Thus it cannot be said to be sufficiently resistant to heat.
The Japanese Patent Publication (kokai) No. 235,835/1985 further discloses that a polyetheric copolymer having a high molecular weight cannot be prepared by simultaneously copolymerizing the raw materials corresponding to the polyetheric copolymer having a molar ratio of the recurring unit (a) to the sum of the recurring units (a) and (b) of less than 0.5.
The present invention has been completed on the basis of the above circumstances.